Par-cooking

Par-cooking refers to the technique of partially cooking foods so that they can be finished later. There are two primary reasons for using this technique. First, it allows foods to be prepared ahead of time, and quickly heated prior to serving. Since the second reheat finishes the cooking process, foods are not overcooked as leftovers often are. This is a common technique in the processed food industry, and most frozen and prepared foods are par-cooked.

A second reason is to take advantage of different cooking techniques. For example, one method of preparing french fries involves first boiling, then frying the potatoes, so they have a crisp exterior and fluffy interior. In stir-fries or other mixed dishes, meats, root vegetables, and other foods that take a long time to cook, will be par-cooked so they finish at the same time as other foods.

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Wikipedia